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排序方式: 共有188条查询结果,搜索用时 828 毫秒
61.
Fumiya Togashi Takeshi Fujita Yasushi Ito Kazuhiro Nakahashi Yoshikazu Makino 《国际流体数值方法杂志》2005,48(8):801-818
Flows around the NAL jet‐powered experimental airplane with a small rocket booster under the fuselage are computed by solving the Euler equations using the overset unstructured grid method. The main objective of the present study is to evaluate the effect of a small rocket booster, which accelerates the airplane to supersonic speed, on the aerodynamic performance of the airplane during the ascent flight and the booster separation. Two unstructured meshes, one for the airplane and one for the booster, overlap. For the accurate separation simulation, the two bodies are in contact at first, and then the booster mesh is contact mesh is moved relative to the airplane mesh to evaluate flow interactions between two bodies. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
62.
Electrochemical principles provide key techniques to promote the construction of bio/chemical microsystems of the next generation. There is a wealth of technology for the microfabrication of bio/chemical sensors. In addition, microfluidic transport in a network of flow channels, pH regulation, and automatic switching can be realized by electrochemical principles. Since the basic components of the devices are electrode patterns, the integration of different components is easily achieved. With these techniques, bio/chemical assays that require the exchange of solutions can be conducted on a chip. Furthermore, autonomous microanalysis systems that can carry out necessary procedures are beginning to be realized. In this article, techniques developed in our group will be comprehensively introduced. 相似文献
63.
Systematic approach to optimize a pretreatment method for ultrasensitive liquid chromatography with tandem mass spectrometry analysis of multiple target compounds in biological samples 下载免费PDF全文
Kazutaka Togashi Kuninori Mutaguchi Setsuko Komuro Makoto Kataoka Hiroshi Yamazaki Shinji Yamashita 《Journal of separation science》2016,39(16):3212-3220
In current approaches for new drug development, highly sensitive and robust analytical methods for the determination of test compounds in biological samples are essential. These analytical methods should be optimized for every target compound. However, for biological samples that contain multiple compounds as new drug candidates obtained by cassette dosing tests, it would be preferable to develop a single method that allows the determination of all compounds at once. This study aims to establish a systematic approach that enables a selection of the most appropriate pretreatment method for multiple target compounds without the use of their chemical information. We investigated the retention times of 27 known compounds under different mobile phase conditions and determined the required pretreatment of human plasma samples using several solid‐phase and liquid–liquid extractions. From the relationship between retention time and recovery in a principal component analysis, appropriate pretreatments were categorized into several types. Based on the category, we have optimized a pretreatment method for the identification of three calcium channel blockers in human plasma. Plasma concentrations of these drugs in a cassette‐dose clinical study at microdose level were successfully determined with a lower limit of quantitation of 0.2 pg/mL for diltiazem, 1 pg/mL for nicardipine, and 2 pg/mL for nifedipine. 相似文献
64.
Ishizaka K Eguchi R Tsuda S Yokoya T Chainani A Kiss T Shimojima T Togashi T Watanabe S Chen CT Zhang CQ Takano Y Nagao M Sakaguchi I Takenouchi T Kawarada H Shin S 《Physical review letters》2007,98(4):047003
We investigate the temperature (T)-dependent low-energy electronic structure of a boron-doped diamond thin film using ultrahigh resolution laser-excited photoemission spectroscopy. We observe a clear shift of the leading edge below T=11 K, indicative of a superconducting gap opening (Delta approximately 0.78 meV at T=4.5 K). The gap feature is significantly broad and a well-defined quasiparticle peak is lacking even at the lowest temperature of measurement (=4.5 K). We discuss our results in terms of disorder effects on the normal state transport and superconductivity in this system. 相似文献
65.
Kashiwagi T Amemiya F Fuchigami T Atobe M 《Chemical communications (Cambridge, England)》2012,48(22):2806-2808
We have successfully demonstrated that a microflow reactor is extremely useful in controlling reactions involving an unstable o-benzoquinone. The key features of the method are an effective o-benzoquinone generation and its rapid use for the following reaction without decomposition in a microflow system. 相似文献
66.
Fumihiro Ito 《Tetrahedron letters》2009,50(46):6252-8013
A new ionization method that uses metal-complex-based ionization probes containing the 2,6-bis(oxazolinyl)pyridine (pybox) ligand is presented. This method was proven to effectively ionize large complex molecules, including biomolecules. The preparation of the charged probes and their application to the ionization of biomolecules using cold-spray ionization mass spectrometry are shown. 相似文献
67.
Hideaki Takahashi Fumihiro Miki Hajime Ohno Ryohei Kishi Suguru Ohta Shin-ichi Furukawa Masayoshi Nakano 《Journal of mathematical chemistry》2009,46(3):781-794
The reaction mechanism for the dehydration of 1,4-butanediol in hot water has been investigated by means of the hybrid quantum
mechanical/molecular mechanical approach combined with the theory of energy representation (QM/MM-ER). We have assumed that
the proton transfers along the hydrogen bonds of the water molecules catalyze the reaction, where the transition state (TS)
forms a singlet biradical electronic structure. It has been revealed by the simulation that the biradical electronic state
at the TS changes to zwitterionic structure in solution due to the hydration of the polar solvent. Such the electronic structure
change gives rise to the substantial stabilization of the TS in hot water. As a result, the water-catalytic path becomes more
favorable in aqueous solution than another possible path that proceeds without proton transfers as opposed to the reaction
mechanism in the gas phase. Furthermore, the activation free energy computed by the present method is in excellent agreement
with the experimental result. 相似文献
68.
Fumihiro Chiba Teruo Ushijima 《Journal of Computational and Applied Mathematics》2009,233(4):1155-1174
Our fundamental solution method gives an analytic representation of the approximate solution for the reduced wave problem in the exterior region of a disc. The asymptotic behavior of this representation yields an approximate formula for the scattering amplitude. An error estimate for this formula is given. We add two numerical tests: the numerical estimate of errors; and profiles of scattering cross sections and the far-field coefficient. Both tests include cases of high wave numbers. 相似文献
69.
70.
Xiaobin Ding Jiaoxia Yang Linfan Zhu Fumihiro Koike Izumi Murakami Daiji Kato Hiroyuki A. Sakaue Nobuyuki Nakamura Chenzhong Dong 《Physics letters. A》2018,382(34):2321-2325
A detailed-level collisional-radiative model for the M1 transition spectrum of the Ca-like W54+ ion as observed in an electron beam ion trap (EBIT) was constructed based on atomic data calculated by the relativistic configuration interaction method and distorted wave theory. The present calculated transition energy, rate and intensity of W54+ M1 transitions are compared with previous theoretical and experimental values. The results are in reasonable agreement with the available experimental and theoretical data. The synthetic spectrum explained the EBIT spectrum in the 12–20 nm region, while a new possibly strong transition has been predicted to be observable with an appropriate electron beam energy. The present work provides accurate atomic data that may be used in plasma diagnostics applications. 相似文献